The h Bar

10:00 PM

heh

@JakeRose (I'm afraid I probably don't have much that's useful to share on that one.)

How come? @EmilioPisanty

Does anybody know good places to apply for summer internship projects? (Im a first year uk Natsci student in cambridge btw)

Emilio Pisanty

@JakeRose it's been a significant time since I needed to revise for exams, and I never did feel like I needed to revise that much.

Jake Rose

Ive applied a bunch but I dont think Ill get any of them (mostly meant for 2nd and 3rd years) or they just have a heavy bias on their own students

@EmilioPisanty Fair enough I can understand that

dmckee

HEre is the project's current membership: alpha.web.cern.ch/people

Emilio Pisanty

@JakeRose you should ask staff at your institution

dmckee

10:02 PM

And I know, at most one of those people to any significant degree.

@JakeRose I know a couple of good places near Joplin, Missouri, USA.

@JakeRose ::shakes head to clear the confusion always caused by the way other English speakers use 'revise':: The starting place is working problems.

Especially looking for problem which you should be able to do but can't seem to get right.

Emilio Pisanty

@JakeRose but it's much easier if you have at least some idea of the type of physics you want to do

dmckee

Those expose weakness in either your conceptual understanding or your process.

Jake Rose

Luckily my supervisor gave me worked solutions to all the previous tripos quesitons so revising is a ton easier

Emilio Pisanty

... which is a hard question indeed, but the hard questions in life don't get solved by not tackling them ;-)

Jake Rose

Just had a look at the cockcroft institute

Bernardo Meurer

10:05 PM

@EmilioPisanty Hire me

Jake Rose

A bus ride from my house

But, boom, only do internships for 2nd and 3rd years

Emilio Pisanty

@BernardoMeurer I'm a lowly postdoc

where would I get money to hire people?

Bernardo Meurer

@EmilioPisanty I thought postdocs could hire people?

@dmckee Hire me

Emilio Pisanty

@BernardoMeurer that's...

charmingly naive ;-)

2

dmckee

@BernardoMeurer I'm on the market myself and officially out of the hiring look.

Jake Rose

10:06 PM

@EmilioPisanty Tbh Im not sure what area I myself want to go into. My maths abilities arent good enough for a lot of the more mathematical stuff so I guess it would have to be something lab based for this year

Emilio Pisanty

@JakeRose it's a first-year internship

Jake Rose

(I do love space related things and its likely what Ill work on in the future but Ive applied for the few there is)

Emilio Pisanty

you're not committing the entirety of your career

Bernardo Meurer

@EmilioPisanty Dammit :P

Jake Rose

@EmilioPisanty Oh I agree

Bernardo Meurer

10:07 PM

@dmckee How's that going for you?

Jake Rose

But Im trying to say I dont have any preference

Bernardo Meurer

I find plenty of open dev jobs often, if you're interested

Jake Rose

Id like to just try something and see if I like it

Emilio Pisanty

... so choose something that sounds nice, and you'll find out whether it's your thing or not with plenty of time to switch tracks afterwards

dmckee

@BernardoMeurer So-so. A few call backs. One telephone interveiw. A whole lot of nothing.

Emilio Pisanty

10:08 PM

@dmckee too much nothing?

Bernardo Meurer

@dmckee What kind of jobs are you looking for?

Emilio Pisanty

PETER, PAUL & MARY - "Too Much Of Nothing" 1969

►

dmckee

@BernardoMeurer I am interested in programming jobs, but I don't want the salary scale for a entry-level general programmer.

Jake Rose

@EmilioPisanty The problem Im having isnt finding one I like its finding one at all

dmckee

So my focus has been on scientific programming jobs.

Bernardo Meurer

10:08 PM

@dmckee I think I can help you, or at least try. What's your email?

dmckee

Those are rarer but they pay something like my current salary and up.

Bernardo Meurer

If you don't want to post it here reach me at meurerbernardo at gmail dot com

Emilio Pisanty

@BernardoMeurer I am looking for someone to take up a couple of projects I don't have enough bandwidth for

dmckee

mckee hyphen d at mssu dot edu

Until the end of summer, anyway.

Emilio Pisanty

particularly studying HHG within the SFA on an extension to a fully quantum-optical formalism

... if that's your cuppa tea

Bernardo Meurer

10:10 PM

@dmckee Noted :)

Emilio Pisanty

@dmckee ah ha

Bernardo Meurer

@EmilioPisanty I don't think I have the necessary knowledge to tackle that, even if I am interested in quantum

Jake Rose

Does anybody have any links to universities they could politely ask if theyd like to talk to a peasant first year xxxxx

Emilio Pisanty

@dmckee is it, in fact, a Great Day to be a Lion?

@JakeRose 'fraid not

dmckee

@EmilioPisanty I was actually pretty optimistic when I thought I had a career here. There is a commitment to being a real institution of higher learning and not many places to go but up.

But, of course, up is the only choice because we're starting from a pretty low place.

The physics majors are ... interesting.

Emilio Pisanty

10:12 PM

@dmckee "everything anyone says before the word 'but' is horseshit"

Bernardo Meurer

@dmckee Couldn't you go back to UCSB?

dmckee

They are mostly woefully unprepared, but their potential is amazing. If only they would take their math seriously and learn how to work hard at this stuff.

Bernardo Meurer

Then you could dine me and wine me like Daniel

dmckee

And could get by without working a 40 hour/week side job.

@BernardoMeurer more charming naivety.

Emilio Pisanty

@dmckee that sounds like a bigger killer than the first two

dmckee

10:15 PM

@EmilioPisanty Yeah. The others would be solvable without that. It might take tongs and hot irons, but we could solve them.

Bernardo Meurer

@dmckee news.ycombinator.com/item?id=16735011

Check that, a lot of opportunities

Emilio Pisanty

@dmckee ah, there's a picture on the staff page

interesting hairdo

Bernardo Meurer

@EmilioPisanty Link?

dmckee

I'm open to a startup, but it has to be one that is paying a real salary and providing real benefits, so I would be coming in late in the cycle.

Emilio Pisanty

@BernardoMeurer I.... don't think so

it's easy enough to find

physical-science-faculty.php

dmckee

10:17 PM

@EmilioPisanty Yeah. I've never cared much beyond "it doesn't stink, stays out of my face and doesn't get caught in machines."

Emilio Pisanty

lol, fair enough

the "sticking straight up" is an interesting solution to the "stays out of my face" requirement

Jake Rose

Hey guys when deriving the impedance of a inductor from the voltage current relationship I keep gettin a minus sign?

Bernardo Meurer

@EmilioPisanty I can't seem to fin that? Nor do I find a page for the physics dpt

Jake Rose

Ill type it up in latex one sec

dmckee

@BernardoMeurer We are a department of chemical and physical sciences. Small school.

Emilio Pisanty

10:19 PM

@BernardoMeurer c'mon, you're supposed to be the internet whizz kid

Bernardo Meurer

Ah, found it

Emilio Pisanty

it's literally username institution acronym at search engine

Bernardo Meurer

@dmckee You are much younger than I expected!

Emilio Pisanty

@BernardoMeurer did you also expect him to be black & white in person?

dmckee

@BernardoMeurer I just look younger. Fifty is the train at the end of the my tunnel these days.

Bernardo Meurer

10:20 PM

@EmilioPisanty Yeah

dmckee

My father switched from "young" to "old" at about fifty-five.

Jake Rose

$E=-L \frac{dI}{dt}$
$Given I is of the form I=I_0 e^{iwt}$
$E=-Liwe^{iwt}$
$Z=-iwL$

Bernardo Meurer

What's with the soul stare though? :P

Emilio Pisanty

@BernardoMeurer I mean, while we're on the 'charming naïveté' theme

Jake Rose

I always fuck up the spaces

Where have I messed up with the -?

Emilio Pisanty

10:21 PM

@JakeRose that is... not very readable

Bernardo Meurer

@EmilioPisanty I'm glad you find me charming :P

Jake Rose

One sec

Bernardo Meurer

@EmilioPisanty Am I charming enough that you'll hire me for the summer?

Jake Rose

How do you write a derivative?

Emilio Pisanty

@BernardoMeurer are you charming enough that I would hire you for the summer if I had money to hire people?

Bernardo Meurer

10:22 PM

Damn Dr. Gilbert-Saunders is kind of cute

Emilio Pisanty

trick question, answer is both yes and no without incurring contradictions

Bernardo Meurer

::transfers to missu::

@EmilioPisanty Yes, yes I am

You could not resist my Brazilian voluptuousness

Emilio Pisanty

@JakeRose what, $\partial$ $\partial$?

Bernardo Meurer

And also, we have to stick together as the Latino axis of the h-bar

Jake Rose

$E=-L \frac{dI}{dt}$
Given I is of the form $I=I_0 e^{iwt}$
$E=-Liwe^{iwt}$
$Z=-iwL$

0celo7

10:23 PM

@ACuriousMind is an expert in being an Axis power

Jake Rose

Thats better

Emilio Pisanty

@JakeRose that $I=I_0 e^{i\omega t}$ looks rather un-kosher

Jake Rose

What do you mean?

Emilio Pisanty

you want either $e^{-i\omega t}$ or $e^{j\omega t}$

when dealing with phasors, sign conventions are quite important

dmckee

@BernardoMeurer Lynell is a dinkum person. But you'd been competing with the memory of her rodeo cowboy late husband.

Emilio Pisanty

10:24 PM

physicists tend to use $i$ for $\sqrt{-1}$ and they denote oscillations in time as $e^{-i\omega t}$

engineers tend to use $j$ for $\sqrt{-1}$ and they denote oscillations in time as $e^{j\omega t}$

Bernardo Meurer

@dmckee I look good in a cowboy hat

Jake Rose

mhm

Bernardo Meurer

And also, my condolences to her, I obviously just meant it as a compliment

Emilio Pisanty

the upshot is that you can just identify $j=-i$ to translate between engineer-speak and physics

dmckee

@BernardoMeurer But how do you do distracting a 600 kg bull so the rider can get away?

Jake Rose

10:25 PM

In our lectures we didnt bother with a negative sign

David Z

5

Q: How to quit physics.stackexchange.com completely?

I was wondering how to completely leave this community. Please guide me. I have gone through FAQ section but of no use. What should I do ?

support

Jake Rose

Is there anything wrong with not using a negative sign?

Bernardo Meurer

@dmckee I grew up in a farm, so I think I can handle that?

Emilio Pisanty

@dmckee what on Earth is a "dinkum person"?

Bernardo Meurer

@EmilioPisanty Honest, genuine, authentic, true

Emilio Pisanty

10:26 PM

@BernardoMeurer huh

dmckee

"Dinkum" is word from Australian. I picked it up reading The Moon is a Harsh Mistress.

Bernardo Meurer

That's the definition of dinkum, I think

Emilio Pisanty

@JakeRose that's... kinda bad

Jake Rose

What is the benefit of using the negative sign?

Emilio Pisanty

@JakeRose you get the physics right?

Lenz's law

Lenz's law (pronounced ), named after the physicist Heinrich Friedrich Emil Lenz who formulated it in 1834, states that the direction of current induced in a conductor by a changing magnetic field due to induction is such that it creates a magnetic field that opposes the change that produced it. Lenz's law is shown by the negative sign in Faraday's law of induction: E = − ∂ Φ ∂ t ...

Jake Rose

10:27 PM

Sure do

Emilio Pisanty

the sign on the inductance is important enough to be a named physical law

so, I'd say, pretty important

Jake Rose

I included lenzs law in the initial expression?

dmckee

@JakeRose When you put a complex number up there you get the dying amplitude solution.

Assuming the real part is positive. But that's the usually choice.

Emilio Pisanty

@JakeRose you're in that area.

the important thing with phasors is that quite often there aren't "wrong" signs

there's just incompatible sign conventions

so your sign isn't wrong until you state what result you're comparing with and what sign convention that work uses

Jake Rose

Mhmm

Hes been consistent with his lecture notes

And so Ive never seen the more popular convention before

Every lecturer in cambridge has a thing for not using the rest of the worlds conventions I swear

Emilio Pisanty

10:30 PM

@JakeRose what do you mean by that?

it's pretty pointless to say which convention is "more popular"

there's almost certainly a whole ton more engineers using the $e^{j\omega t}$ convention than there are physicists using $e^{-i\omega t}$

Jake Rose

Does this change in convention explain why the negative sign appears?

Emilio Pisanty

but that doesn't mean that the engineers are "right"

@JakeRose it might, or it might not

Jake Rose

Fair enough

Emilio Pisanty

there's not enough context to tell

Jake Rose

I personally dont think it does

$E=-L \frac{dI}{dt}$

Emilio Pisanty

10:32 PM

@JakeRose you haven't given enough information to tell so it really is impossible, and pointless, to speculate any further.

Jake Rose

This equation is right and you understand it right?

Emilio Pisanty

@JakeRose that equation is meaningless without more context.

Jake Rose

The voltage across a inductor

Emilio Pisanty

@JakeRose you're seriously using $E$ for voltage?

Jake Rose

$\epsilon$

dmckee

10:33 PM

Perhaps $\mathcal{E}$ for the EMF.

Jake Rose

Yeah thats what I was looking for thanks @dmckee

Emilio Pisanty

@JakeRose I guess it does have enough information, given that you specify which way you're measuring the voltage and the current

I don't remember the sign conventions by memory

dmckee

Which is (a) not a force, (b) denominated in volts but (c) shouldn't be called a potential.

Emilio Pisanty

the thing to check for is whether your predict states that the EMF goes 90° out of phase ahead of or behind the current

dmckee

^ That.

Emilio Pisanty

10:36 PM

that is the objective physical standard you should be holding yourself (and your maths) to

and which does not depend on the particulars of the sign convention in use

1

Q: What does $\pi^2$ represent in real life?

I am in physics 2 and learning about induction and inductance, as well as LC and RLC circuits, I am encountering the value $\pi^2$ a lot. I wanted to know what $\pi^2$ represents, either geometrically or physically. For example, I know that $\pi$ is the ratio of circle's circumference to its diam...

electromagnetism classical-mechanics geometry

is that quite on topic?

this is a vaguely similar recent question but the posters appear unrelated?

David Z

Hm... my instinct is to say not on topic, but I'm not sure about that. I can't really pin down a clear reason for it not to be on topic.

dmckee

I always wonder what people expect the answer to those questions to be.

Emilio Pisanty

@dmckee well, here is a sample

don't know if 'elephant in the room' is quite the right description though

0celo7

@EricSilva can u spread the word to invade here

Eric Silva

i actually dont comprehend what happened

0celo7

10:43 PM

My plan to turn the math chat into the new Mos Eisley is proceeding nicely.

Semiclassical

I go away and the math chat has gone Hoth

wtf

0celo7

It's Balarka's fault lol

Joe Stavitsky

Does N_c make 40 degrees with the vertical? i.imgur.com/gmCp8hZ.png

Eric Silva

i was doing my physics homework and wasnt paying attention and it just escalated but looking back at it i dont understand what exactly the problem was

0celo7

Me neither.

He froze the room because of some stuff Balarka did 30 minutes ago

Eric Silva

10:45 PM

was it the goat cuck thing

0celo7

More evidence that a number of the moderators are incompetent

Not anyone in this room of course

Eric Silva

@0celo7 how fast could i read wald if i were insane and didnt socialize for a while

0celo7

Maybe a month? I dunno

You know a lot more than me when I read it

But it took me a while

Eric Silva

how much physics does it demand i know because i literally have only done the intro sequence at this point

0celo7

Not much

Just read it and if you get confused I know it backwards and forwards

I can tell you where to look

Eric Silva

10:49 PM

mmk, i think im gonna pick it up once i take the GRE this week

Zee

Wtf? The room got frozen? Wow ,

It’s like North Korea

0celo7

@Zee I'm surprised you like physics

@EricSilva Do you have time for GMT

right now

Eric Silva

not atm

Zee

I don’t , it’s just the closest thing to the math chat

0celo7

k

Eric Silva

10:53 PM

doing all my hw for this upcoming week so i can focus on GRE prep so i can be done with that

Zee

Ya, we know

Probably looks away from the mirror when he brushes his teeth

0celo7

He froze it for no apparent reason

dmckee

@Zee and

Zee

No, he froze it couse he has no power in real life so now he has a little bit of power on this fantasy land we call chat , and suddenly he feels hes

dmckee

@Zee Here's a hint: calling moderators names for moderation actions and stating or implying that they are acting like totalitarians is not a great plan.

Zee

10:58 PM

I call it the way I see it

0celo7

@dmckee Frankly, the moderation action in this case is unnecessary. The guy froze the room for something someone did 30 minutes ago.

Zee

Collective punishment is THE sign of a totalitarian rule

0celo7

The rest of us were peacefully chatting and he just froze it. I don't get it.

Eric Silva

i think comparing an internet chat to a political regime is a little weird

dmckee

@0celo7 This is a perfectly fine way to express that opinion. Name calling (even by implication) is "Not nice." within the meaning of the rule.

Zee

11:00 PM

People are people , controlling a chat or a country

You didn’t roll over for the party, here, you get 30 days in jail

Same exact concept

@dmckee are you a teacher ?

0celo7

Were you kicked or something?

Balarka Sen

It was I.

Zee

I don’t think so , although that happens often

This isn’t about you anymore @BalarkaSen

0celo7

wtf, Zee, didn't know you were such a Freedom lover

Balarka Sen

@Zee I think the moderators overreacted, because other than me none said anything that was controversial, or flag-worthy, or flag-fought with others. But I think your conspiracy theory is a little ridiculous lol

0celo7

11:05 PM

We can be friends after all

@BalarkaSen The mods will come for our guns next

@dmckee do SE members have a bill of rights

Eric Silva

@BalarkaSen i think some of the notation stuff was controversial enough to bury the room forever tbh

Zee

It’s not a conspiracy theory , it’s basic human nature , you let people take an inch and they will demand a mile

@0celo7 we are all men of principle here , it’s just a matter of having the guts

dmckee

@0celo7 Why would they?